It is known from the prior art for highly dimensionally accurate half-shells to be produced by deep-drawing a blank.
For example, from DE 10 2007 059 251 A, it is known for highly dimensionally accurate half-shells to be produced in a two-stage process. For this purpose, pre-shaped half-shells are firstly produced, which pre-shaped half-shells have excess material over the entire cross section owing to their geometrical shape. Subsequently, the pre-shaped half-shells are upset into their final shape by way of a further pressing process. A half-shell produced in this way exhibits particularly high dimensional accuracy, as the springback of the half-shell has the introduced upset superposed thereon.
A disadvantage of said production method is however that the pre-shaped half-shells must generally undergo further trimming in order that they exhibit the desired dimensions, in particular with regard to the jacket height. To optimize the process chain, it is known, for example from DE 10 2011 050 001 A1, for the final trimming to be integrated into the deep-drawing process. To produce flangeless drawn parts, it is provided in said document that the flange region of the half-shell is trimmed in the region of the die rest surface. Subsequently, the pre-shaped half-shell produced in this way is calibrated in the same tool by way of a upset shoulder arranged on the drawing punch. Said method however furthermore has the disadvantage that excess blank material becomes trimmed waste, and the integration of the cutting edge into the deep-drawing die is subject to a high level of tool wear. Furthermore, it cannot be adequately ensured that the blank does not change its position during the deep-drawing process, resulting in dimensional inaccuracies of the pre-shaped half-shell being generated, which in turn necessitate trimming in the flange or jacket region.
EP 2 125 263 B1 proposes that, to optimize the efficiency of the temperature-controlled deformation of hot-rolled steel by deep drawing, both the deformation and the calibration of the component be performed in one drawing die. To fix the blank during the deformation process, said blank is clamped between the punch and the die base, which is displaceable parallel to the direction of movement of the punch, and said blank is deep-drawn in guided fashion in the clamped state. Subsequently, the component is stamped by virtue of a further upset shoulder being moved against it. Said method, too, has the disadvantage that the tools for the production of a deep-drawn part are complex.